Abstract

The size–age structure, growth, and maturation of the spotted catfish Arius maculatus (Thunberg, 1792) from the Hau River estuary, Mekong Delta, Vietnam, were studied for the first time. A total of 460 fish specimens collected from January to March 2019 were examined. The annuli on the otoliths were visualized; their formation may be related with the alternation of the dry and rainy seasons. The male to female ratio in the catches was 1 : 1.81. The proportion of males decreased in the older age groups. The maximum total body length of the females was 21.9 cm; for the males, it was 23.7 cm. The maximum recorded age of females in catches was 7+; for males it was 8+. No inter-gender differences in growth were detected. The parameters of the von Bertalanffy equation for both sexes according to empirical data were as follows: L_∞ = 28.3 cm; k = 0.15/yr; t₀ = –1.03 yr; growth performance index, φ = 2.08. The coefficients of the relationship between mass and length were as follows: a = 0.0054; b = 3.22. Maturation began at a body length of 13 cm at an age of 3 yr and ended at a body length of 18 cm at an age of 6 yr; 50% of the individuals became mature at a body length of 15 cm at an age of 4 yr. No inter-gender differences in the timing of maturation were found. A. maculatus from the Mekong Delta is characterized by a low growth rate compared to other populations, which may be associated with the labile habitat conditions in the estuary zone.

中文翻译：

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越南湄公河三角洲斑Cat鱼（Arius maculatus）的大小，年龄结构，生长和成熟度（Thunberg，1792年）（Siluriformes：Ariidae）

摘要

斑cat鱼（Arius maculatus）的大小-年龄结构，生长和成熟首次研究了越南湄公河三角洲Hau河口（Thunberg，1792年）。从2019年1月至2019年3月，共检查了460个鱼标本。耳石上的瓣环可视化；它们的形成可能与旱季和雨季的交替有关。渔获物中的男女比例为1：1：1.81。年龄较大的人群中男性比例下降。雌性的最大总长度为21.9厘米；对于男性，则为23.7厘米。渔获物中女性的最大记录年龄为7岁以上；男性为8岁以上。未检测到性别间的增长差异。所述贝塔朗菲方程男女根据经验数据的参数如下：大号_∞ =28.3厘米; k = 0.15 /年；t ₀ = –1.03年；生长绩效指数，φ= 2.08。质量和长度之间的关系的系数如下：a＝ 0.0054；和a＝ 0.0054。b = 3.22。在3岁时开始于体长13厘米，在6岁时结束于体长18厘米。50％的人在4岁时的身长为15厘米时已经成熟。在成熟时间上未发现性别间差异。与其他种群相比，湄公河三角洲的黄斑曲霉的特征在于生长速率低，这可能与河口区的不稳定栖息地条件有关。